In vivo Characterization of Epileptic Tissue with Time-Dependent, Diffuse Reflectance Spectroscopy

Abstract

According to the Epilepsy Foundation, about 45,000 children under the age of 15 develop epilepsy each year. One of the long-standing challenges in the field of pediatric epilepsy research is to differentiate between normal and epileptic brain areas. This problem is especially important for children with intractable epilepsy, because surgical intervention must be used to alleviate their epileptic symptoms. Optical spectroscopy may be used to assess the pathophysiological characteristics of the epileptic brain tissue intraoperatively in a non-destructive manner, which, in turn, allows surgeons to plan an epilepsy surgery. Herein, the study is focused on demonstrating the feasibility of using time-dependent, diffuse reflectance spectroscopy specifically to detect pathophysiological characteristics associated with epileptic brain tissue. In a pediatric patient undergoing epilepsy surgery, time-dependent, diffuse reflectance spectra were measured from the epileptic cortex and the surrounding tissue using a fiber-optic spectroscopy system. The system was designed to acquire diffuse reflectance spectra from 300 - 1100 nm at a maximum acquisition rate of 33 Hz. Spectral and temporal variations in the acquired spectral sequences were compared to the corresponding electrocorticographic results, and thosevariations unique to the epileptic cortex were identified using statistical methods. Furthermore, these spectral variations were related to the physiological and morphological characteristics of the brain tissue. The preliminary results obtained from this in vivo study demonstrate the feasibility of differentiating epileptic cortex tissue from normal tissue using time-dependent, diffuse reflectance data.